Unfortunately I am not familiar with a "cained" begonia, but in general the begonias we grow as houseplants do best in bright light and at average household temperatures. It can be helpful to provide an occasional fertilizing with a water soluble or long release fertilizer for foliage plants according to the label instructions, and the plant may need to be repotted if it outgrows its pot. In my experience, the most common reason for lack of flowering is that the plant needs a bit more light. In some cases a plant that is overfertilized will produce excess foliage at the expense of flowers, so make sure you are not overfertilizing. I hope this helps you troubleshoot.